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WorksheetsFGHS AP Chemistry Quiz #11 Unit #03 Exam Review Chemical Rxns
Total questions: 17
Worksheet time: 39mins
In the ion, HAsO42-, what is the oxidation number of arsenic?
-2
+4
+5
-5
When the half-reactions shown below are combined, what is true of the resulting REDOX reaction?
Zn ⇌ Zn2+ + 2e-
Cu2+ + 2e- ⇌ Cu
Four electrons are transfered in the reaction
Zinc metal is reduced
Zinc ions are reduced
Copper ions are reduced
In the reaction between thiosulfate ions (S2O32-) and iodine, the sulfur species is converted to S4O62- and the iodine is converted to iodide ions. Which statement regarding the reaction is true?
The oxidation number of sulfur is the same in the reactants and products
I atoms are oxidized
The oxidation number of iodine changes from 0 to -1
The reaction is not a REDOX reaction
In which of the following does the metal have the same oxidation state?
MnO4-1 and MnO2
MnO4-1 and MnO42-
[Fe(CN)6]4-1 and [Fe(NO3)4]-1
CrO4-2 and Cr2O7-2
When manganate(VII) ions are reduced to Mn2+ ions in acid solution, how many electrons are transferred?
One cannot know without the corresponding oxidation half-reaction
2
5
7
When iron metal is added to a solution of copper(II) sulfate, which statement is true?
A REDOX reaction takes place
The copper ions are oxidized
The copper ions are spectators
Sulfate ions precipitate out
Which of the following reactions could be described as displacement?
Sodium + Chlorine → Sodium chloride
Hydrogen peroxide → Hydrogen + Oxygen
The disproportionation of ClO3- to give hypochlorite ions and chloride ions
Zinc + Sulfuric acid → Zinc sulfate + Hydrogen
In the following reaction, which species is acting as an acid in the REVERSE (right to left) reaction?
NH3 + H2O ⇌ NH4+ + OH-
NH3
H2O
NH4+
OH-
How many moles of hydroxide ions are present, and on which side of the equation, when the half-reaction below is balanced in BASIC solution, using the smallest possible integers?
MnO4- → MnO2
2 on the reactant side
2 on the product side
4 on the reactant side
4 on the product side
Which of the following reactions represents both an Acid-Base neutralization, AND a precipitation reaction?
Hydrochloric acid + Sodium hydroxide
Lead(II) nitrate + Sodium chloride
Sulfuric acid + Barium hydroxide
Sulfuric acid + Potassium hydroxide
consider the two standard reduction potentials shown below.
Cu2+ + 2e- → Cu (+0.34V)
H+ + e- → ½H2 (0.00V)
If the two half-cells below were combined in a standard, galvanic cell, what would be the correct chemical equation to represent the spontaneous REDOX process?
Cu(s) + ½H2(g) → Cu2+(aq) + H+(aq)
Cu(s) + 2H+(aq) → Cu2+(aq) + H2(g)
Cu(s) + H+(aq) → Cu2+(aq) + ½H2(g)
Cu2+(aq) + H2(g) → Cu(s) + 2H+(aq)
consider the two standard reduction potentials shown below.
Cu2+ + 2e- → Cu (+0.34V)
H+ + e- → ½H2 (0.00V)
If the two half-cells were combined in a galvanic cell, what would be the voltage generated the spontaneous REDOX process?
0.00 V
+0.34 V
-0.34 V
+0.68 V
What is always true of all electrolysis processes?
They generate electricity
They have ∆G° vlaues that are positive
They are thermodynamically favored
They never need an extrnal source of energy to make them occur
The metal indium, is known to exist in an oxidation state of +3. What approximate mass of indium (molar mass = 114.82 g) will be produced during the electrolysis of a molten salt that contains In3+, if a current of 10.0 amps is passed through the electrolyte for a period of 50.0 hours?
50.0 g
115 g
714 g
1.80 x 106 g
The purpose of the salt-bridge in a galvanic cell is
To allow the passage of ions and to precipitate out ions of either the reduced or oxidized species
To provide electrons to the cell
To allow the passage of ions to maintain the potential difference between the two half-cells
To allow the passage of electrons between the two half-cells
Which combination of values for ΔG°, Keq and E°, is the most likely?
Negative ΔG°, K < 1 and positive E°
NegativeΔG°, K > 1 and negative E°
Positive ΔG°, K > 1 and positive E°
Negative ΔG°, K > 1 and positive E°
In a simple galvanic cell constructed from the two half-cells shown below,
Cu2+(aq) + 2e- → Cu(s) +0.34V
Zn2+(aq) + 2e- → Zn(s)-0.76 V
Electrons flow toward the zinc cathode where reduction takes place and negative ions from the salt bridge enter the reduced half-cell
Electrons flow toward the copper anode where oxidation takes place and positive ions from the salt bridge enter the reduced half-cell
Electrons flow toward the zinc cathode where oxidation takes place and positive ions from the salt bridge enter the reduced half-cell
Electrons flow toward the copper cathode where reduction takes place and positive ions from the salt bridge enter the reduced half-cell
